Multi-wire connector and plug with selective central key means for different voltages



Feb. 27, 1962 H. HUBBELL MULTI-WIRE CONNECTOR AND PLUG WITH SELECTIVE CENTRAL KEY MEANS FOR DIFFERENT VOLTAGES Filed March l?, 1958 2 Sheets-Sheet 1 INVENTOR ATTO RNEYS.

Feb. 27, 1962 H. HUBBELL 3,023,394

MULTI-WIRE coNN o ND PLUG WITH SELECTIVE CENT L Y NS FOR DIFFERENT VOLTA Filed March 17, 1958 2 Sheef.s-Sheel'I 2 INVENTOR ATTORNEY United States Patent Oiice 3,023,394 Patented Feb. 27, 1962 tion of Connecticut Filed Mar. 17, 1958, Ser. No. 721,856 6 Claims. (Cl. 339-186) This invention relates to electrical connectors and cooperating plugs, and has for an object to provide a multiwire connector and plug with selective key means for diierent voltages.

Another object is to provide a device of this character with a selective key means adapted for use either with the locking type of connection where the connector and plug are locked by relative turning movement, or with the standard non-locking type. l

Another object is to provide'a device of this character which will identify theconnectors and plugs for diierent polariti'es and different .voltages for'speciallapplicatons.

Still another object is ,to provide this-type' offelectrical connector and plug which'will preventthe use of either the: plug or connector designed 'for onervoltage'for polarity' with a plug or connector designed for another'voltage-or polarity. f v f j With the foregoing and .other objects in ^view,;. I; have devised the construction illustrated in the accompanying drawing forming a part of this specication. Itis, however, to be understood the invention is not limited to thev speciiic details of construction and arrangement shown but may embody various changes and modifications within the scope of the invention. 1

In these drawings:

p FIG. 1 is a perspective viewof a connector involving this invention;

FIG. 2 is a similar view of with this connector;

FIG. 3 is an end view of the connector of FIG. 1 on a reduced scale showing the plug contacts inserted therein in section and in an unlocked position;

FIG. 4 is a similar view showingthe the locked position; v

FIG. 5 is a longitudinal section through lthe connector of FIG. 3 substantially on line -5-5 thereof;

FIG. 6 is a transverse section substantially on line 6-6 of FIG. 5; v v

FIG. 7 is a perspective view of the central key memplug contacts in ber shown in FIGS. 1 and 3 to 6 removed from the connector;

FIG. 8 is an end view of the plug of FIG. 2 on a reduced scale;

FIG. 9 is a transverse section substantially on line 9 9 of FIG. 8 showing the contactblades in elevation;

FIG. l0 is a bottom plan view of the upper member of FIG. 9 removed from the plug, the ligure being substantially on the level of line 10-10 of FIG. 9;

FIG. l1 is a detail section on an enlarged scale showing one means of mounting the central key member of the connector;

FIG. 12 is a similar view showing another means of mounting the key member, but showing the key member in elevation;

FIG. 13 is an end view of a non-locking type of conductor;

FIG. 14 is a partial longitudinal section thereof substantially on line 14-14 of FIG. 13;

FIG. 15 is a transverse section substantially on line 15-15 of FIG. 14;

a plug which may be used.

FIG. 16 is a perspective view of the center key of FIGS. 13 to 15 removed from the connector;

FIG. 17 is an end view of a cap or plug which may be used with the connector of FIGS. 13 to 15;

FIG. 18 is a partial side elevation and partial section thereof;

FIG. 19 is a detail section showing another means of mounting the central key, and

FIGS. 20 to 23 are end views of diierent types of center key Which may be used in the connector of this device.

Referring first to the form of device shownin FIGS. 1 to 10, which is of the locking type, wherein the plug may be locked against accidental withdrawal from the connector by longitudinal pull on the electrical cables connected thereto lby relative turning movements of the connector and plug. The connector 1 is shown in perspective in FIG. 1 and the corresponding plug 2 for use therewith is shown in perspective in FIG. 2, While various de-` tail views of the two members are shownv in FIGS. 3-

to .10. The connector 1 comprises` a body member 3 of any suitable'insulating material, and an end member4 also of insulating material located at one end of the member, 3 and enclosedin a suitable 'protective metal-cap 5, all,- of which are connected together ,by suitable screws 6 passing'longitudinally through thezmembers-S and-4 ,and

threaded into the end wall ofthe cap 5. The member '3 isiprovidedwith suitable chambersqor compartments 7 for suitable receptacle contacts 8. The number of these contacts may vary, but in the arrangement shown there are four of them equally spaced about the longitudinalk axis of the connector, and these are adapted for con nection -to suitable lead wires 9 in a conductor cable 10.` One of these contacts may be a grounded contact, andvv they may also be polarized. the member 3 are curved elongated slots 11 and 12 lead-v v ing to the chambers 7 and the receptacle contacts mounted therein. These slots are adapted for insertion.- of the contact blades 13 and 14 of the plug or cap 2. As`

this is the locking type of connector, these blade contactsare widened at their free ends to provide overhanging por. tions 15 and 16, and thus provide overhanging outwardly facing locking shoulders 17 spaced from the top or outerv surface of the insulating body member 18 in which these blades are mounted. The -body of the cap includes ay second insulating member 19 at the inner sideof the` member 18, and both are enclosed in a protective metalcup-shaped cap 20, and all three of these members are connected together by suitable screws 21 passing through the members 18 and 19 and threaded into the end Wall` of the member 2i). The Shanks of the blades 13 and 14- are passed through suitable openings in the member 18 and secured therein by contact-plates 22 riveted tothe inner ends of the Shanks, as indicated at 23, and resting against the inner surface of the member 18. Electric conducting wires 24 in a conductor cable 2S may be con-y nected to these plate contacts by any suitable means, that shown comprising stripping the ends of conductors 24 and laying them across the plates 22 between the insulating members 18 and 19, and then drawing these members together by means of the screws 21 to clamp the conductors 24 against the plates 22. These conductors may be kept separated by transverse members 19a formed as an integral part of the member 19. The contact 14 may be a grounding blade with a laterally bent edge portion 26 for entrance into a similarly shaped portion 27 of the slot 12, to be sure that the plug is inserted in the connector with these grounding contacts in contact.

The receptacle contacts 8 may be of different constructions to cooperate with the plug contacts 13 and 14, but in the arrangement shown they each comprise two spring In the upper end wall of.

members 28 and 29 side by side and connected together by any suitable means such as a shouldered transverse key 38 passing through aligned openings in these two members, as indicated at 31 (FIG. 5) and' riveted over at its inner end as indicated at 32. The contacts 8 are located in the chambers 7 by the opposite ends of keys 30 seating in recesses 30a and 3619 in the inner end of member 3. The free ends of these members 28 and 29 are located in alignment with and at the inner ends of the entrance slots 11 and 12 to receive plug blades 13 and 14 between them. At their opposite ends they are bent laterally, as indicated at 33, to provide at surfaces against which the bared free ends of the conductors 9 are clamped by the end member 4 by drawing this member upwardly by means of the connecting screws 6. They are separated by transverse connecting walls 34 provided as an integral part of the member 4.

The body member 3 is provided with a central longitudinal chamber or passage 35 in which is mounted a central cylindrical key member 36. This key member is provided at its outer end with an entrance opening or passage 37 which may be of different shapes and located in different arrangements with respect to the longitudinalV axis of the member 36, as will presently be described, but in the arrangement shown in FIGS. 1 and 3 to 7 this entrance opening or slot is of angular or L-shape, cornprising two elongated rectangular portions intersecting at one end. This member 36 may be mounted by diierent ways within the member 3, but as shown, the end wall of member 3 is provided with an inwardly facing shoulder` 38 formed by making the opening 39 from the outer end to the chamber 35 of a smaller diameter than this chamber. Similarly, the key member 36 is provided with a reduced end portion 40 to correspond with the portion 39 and provide an outwardly facing shoulder 41 to engage the shoulder 38. The key member 36 may be retained in the chamber 35 by the transverse member 34 engaging its inner end, as shown in FIG. 5, and retaining the shoulder 41 against the shoulder 38. The key member 36 is mounted for limited turning movement in thel member 3, and frictional means is provided to frictionally retain it in the normal retracted position for insertion of the key of the plug and prevent it from shifting from this position by vibration or other inadvertent reasons. This in the arrangement shown comprises a flat bowed spring 42 mounted in a suitable recess 43 in the side wall of the member 36 and frictionally engaging the -walls of the chamber 35 to retain 4the member 36 in its normal retracted position. Extending upwardly from the shoulder 3S are a plurality of curved recesses 44 (FIG. 6) around the reduced portion 49l providing stop lugs 45 between them, and extending upwardly from the shoulder 41 of the member 36 is a stop lug 46 adapted to be seated in any one of these recesses 44, but it is of less length than the recesses 44 to permit limited turning movement of the member 36 in the body member 3.

Mountedk in the center of the body 18 of the plug or cap 2 is a key member 47 projecting from the face of the member 18, the same as the contacts 13 and 14, and

in this cap for use with the connector 1, this key is angularly shaped to correspond with the opening or passage 37 in the key member 36. The key 47 may be mounted in any suitable way, but in the form shown it is mounted in a circular plug 48 located in an opening in the body member 18 with the shank of the key extending through it and riveted over a securing plate 49 at its inner end. This key is rigidly mounted in the member 13, but may be mounted in dierent angular positions about the axis of this plug, as indicated by the dotted lines 47a in FIG. 8. The key 47 may be a grounding contact if desired, and a similar contact (not shown) to engage contact 47 may be mounted in the chamber 36a in key member 36.

As shown by the dotted lines St) in FIGS. 3 and 4,

the. chambers, 7 containing the receptacle contacts, 8, are.

extended beyond the forward ends of the inlet slots 11 and 12, and also the slots 11 and 12 are longer than the width ofthe shanks 13u of the contacts 13 and 14, but are long enough to admit the widened overhanging end portions 15 and 16 of the plug contacts. Thus these plug contacts may be inserted in the inlet slots 11 and 12 as shown in FIG. 3, with the narrower portions 13a of the blade contacts in one end of the slots. This permits the broadened portions 15 and 16 to enter into the chamber 7 and engage the receptacle contacts 8, with the overhanging shoulders 17 inwardly of the outer ends 7a of the chambers 7. Then by turning the plug clockwise, as viewed in FIG. 3, the blade contacts 13 and 14 are shifted in the slots 11 and 12 to the position of FIG. 4 to carry the widened portions 15 and 16 and the outwardly facing overhanging shoulders 17 under the walls 7a at the opposite portion of the cham-bers 7 provided by the extensions 50. This will lock the blades and the cap or plug in the connector against accidental withdrawal by tension on the conductor cables connected to the cap and connector. As the contact blades are inserted in the slots 11 and 12, the key 47, properly placed in the plug, is inserted in the angular inlet opening 37 in the key 36 and due to the. length of. the recess 44 in which the lug 46 is located being greater than the width of this lug, this key 47 also rotates the key member 36 with turning movement of the plug to the locked position. Movement of the key member 36 may be limited by one of the stop lugs 45. Unlocking` and removal of the plug 2 from the connector 1: may be eected. by rst turning the plug 2 in the reverse or counterclockwise direction to shift the shoulders4 17 from their overlapping positions with the end walls 7a of thel chamber 7 to the positions of FIG. 3, and then withdrawing by longitudinal pull on the plug to separate it from the receptacle. In this movement the key 37 also turns the`v key member 36 backwardly to its original or normal position.

It will be seen that for any given position of the key member 36 and its angular slot or opening 37, contacts of the plug 2 can be` inserted in this connector 1 only when the key member 47 is correspondingly located to enter the opening 37 when the proper contacts 13 or 14 enter the proper slots 11 and 12. Thus, with any given connector 1 only the proper plug with the properly located key 47 can be inserted in the connector with any given angular position of entrance slot 37. This will therefore prevent insertion of the improper plug in the receptacle. It will, therefore, for example, prevent a polarized plug or cap 2 being Kinserted in the improper receptacle 1, and vice versa. It will also prevent, for example, the insertion of a 220-volt plug into a connector connected in a higher voltage circuit, say 270. volts. Also the key member 36 with its-opening 37 may be located in different angular positions -about the axis of the connector 1 by locating its lug 46 in another one of the curved recesses 44. In the construction shown, as there are four different recesses 44, this member 36 and its slot 37 may be located in any one of these four different positions to receive only the plugs 2 with the properly and correspondingly located keys 47.

kFIG. 11 shows a modied arrangement for mounting the key member 51 corresponding to the key member 36. In this case, instead of the reduced end portion 40, the outer end is somewhat enlarged, as shown at 52, and the passage in the body, to agree with the connector to receive it, is correspondingly enlarged, but although not shown, this member is provided with the lug 46 the same as the member 36 cooperating with recesses 44 in the receptacle body. At its inner end the member 51 is secured by a screw 53 threaded into this member over a retaining washer 54 engaging a shoulder 55 at the inner end of the passage 56. This member 51 may have the same key slot 37 as the member 36 and may turn with key 47.

Another means of mounting the key member 57 correspending to the member 51 is shown in. FIG.. 12. this case the member 57 is provided with a peripheral groove 58 `adjacent its inner end in which `is a spring ringv 59 engaging a shoulder 60 to retain the key member 57 end in which are mounted the receptacle contacts 63. Its v outer end is provided with curved slots 64 for entrance of the blade contacts 65 of the plug or cap 66. The lead wires from the electric cable may be connected to the contacts 63 by any suitable means, either the same as that shown in FIG. 5 by drawing up the screws 61a connecting the members 61 and end member (not shown) with the metal cap 61b, or by binding screws as is common practice. Lead wires from the conductor cable 67 may be connected to the contact blade 65 of the plug in any suitable manner, either the same as that shown in FIG. 9 by connecting screws 77a to cap 77b, or by the commonly used binding post screws. In the center of the body 61 is a longitudinal passage or chamber 68 in which the key member 69 corresponding to the key member 36 is located. The inner portion of this passage is reduced to provide the inwardly facing shoulders 70, and the outer end portion 71 of the key member is also reduced, providing an outwardly facing shoulder 72, and extending outwardly from this shoulder is a lug 73 adapted to seat in any one of a plurality of recesses 74 (FIG. l5) extending outwardly from the shoulder 70. This key member may have the angularly shaped inlet slot 75 corresponding to the slot 37 of the key member 36. To insure that the contact blades 65 of the plug 66 are inserted in the proper inlet slots 64 in the receptacle 61, this plug is provided with an angularly shaped key or blade 76 corresponding to the opening 75. It is rigidly mounted in the body member 77 of the plug by any suitable means, such, for example, as riveting its inner end over a retaining washer 78, as described in connection with the plug 2. It will therefore be seen that with any given position of the key member 69 the plug 66 can be plugged into the receptacle or member 61 in only the one position in which the angular position of the key 76 corresponds to that of the entrance slot 75 in the key member 69. This will prevent using an improper plug 66 with any given receptacle or connector 61. Also, it will be seen that as there are a plurality of recesses 74 in the body member 61 of the connector, in the present instance four, to receive the lug 73 of the key member 69, the key mem-ber 69 with its slot 75 may be located in any one of these four positions, and for a proper plug 66 to be used with any one of these positions its key 76 must be correspondingly located. As in the rst form, the key 76 could be a grounding contact to engage a grounded contact (not shown) in chamber 69a in member 69.

FIG. 19 shows a modified arrangement for mounting a keg member 79 in the body 61. In this case it is a shortened key member provided with a peripheral groove 80l in which may be a spring locking key 81 to engage a shoulder 82 at the outer end of the chamber 68, and this key mem-ber may have the same opening 75 as the key member 69. It has a peripheral flange 83 seating in a recess in the outer end wall of member 61 to limit its inward movement. This member may be used with either the locking or nonlocking type of connector. If with the locking type, it may turn with key 47, the snap ring 81 providing friction to retain it in the normal position.

Although in the devices of FIGS. 1 to 19 they are described as having an angularly shaped slot 37 or 75 for cooperation with a similarly shaped key on the plug or cap, these cooperating openings and keys may be of different` shapes and locations.` Thus, for example, the angularly shaped slot may be arranged with diierent relation to the lug 46 or 73, as shown in FIG. 20, or instead of being an angularly shaped slot it could be a single straight elongated slot 84 eccentrically arranged with respect to the axis of the key members, as indicated in FIG. 21, or it could be a round opening or passage 85 eccentrically arranged with respect to the axis, as shown in FIG. 22. Turning any one of these key members to any one of the four positions permitted by arrangement of lugs 46 or 73, in the receptacle or connector, would prevent plugging in of any cap or connector 2 or 66 unless it is provided with a similarly located and similarly shaped key member 47 or 76. The key members 36 and 69 are not limited to four positions, but by means of correspondingly located recesses for the lugs 73 or 46 they would be located in a number of intermediate positions. In the arrangement of FIG. 23, a single elongated slot 86 may be centrally arranged and it could be arranged in several dierent positions, one being the dotted line position 86a at right angles to the full line position, or it could be arranged in intermediate forty-five'degree positions.

Fromthe above it will beseen that this key arrangement for determining the proper lug or capto be plugged into the receptacle or connector can be used, with either the' plainorsimple plug-in'ltype, or with the interlocking type'of plug-in connector, and that it will effectively prevent plugging of the wrong cap or plug into the receptacle or connector. The widened overhanging portions 15 and 16 of the plug contacts are of sufficient width so that they engage and eiect electrical contact with receptacle contacts in the connector as they are inserted in the slots 11 and 12 by relative longitudinal movement between the plug and connector, and they maintain this electrical contact and connection during the relative turning movements of the plug and connector to and from the interlocked position.

Having thus set forth the nature of my invention I claim:

l. A multi-wire connector and plug, said connector comprising an insulating body member provided with chambers for receptacle contacts and a series of contact blade entrance slots leading to said chambers, receptacle contacts in the chambers, said plug including an insulating body and Contact blades mounted on said body for insertion in the slots in the connector to engage the contacts therein, interlocking means to prevent separation of the plug and connector mounted to become etfective and inelective by relative turning movement between the plug and connector, said interlocking means being arranged to become effective by relative turning movement between the connector and the plug only after the contact blades have been inserted in the slots in the connector and are in engagement with the receptacle contacts, an insert mounted in the connector body for limited turning movement therein and provided with a key opening having eccentric portions, and a key projecting from the plug body of the same shape as the opening in the insert and positioned in the same eccentric position relative to the axis of the connector body as the opening in the insert so as to enter said opening only when the contact blades of the plug are in position to enter predetermined slots of the connector, said insert adapted to turn with the key on the relative turning movements of the plug and connector.

2. A multi-wire connector and plug according to claim 1 in which the key opening includes a rectangularly shaped slot at least a portion of which is eccentrically located in the end of the insert, and the key in the plug includes a similarly shaped and located rectangular portion for insertion therein.

3. A multi-wire connector and plug according to claim l, in which there are means for mounting the insert and key in diierent angular positions about the longitudinal axes of the connector and plug respectively.

t 4. A multi-Wire connector and plug according to claim 1, in which the key opening in the insert is an angularly shaped slot in the outer end of the insert, the key projecting from the plug body is of the same shape and located in the same eccentric position relative to the axis of the connector body as the key opening when the plug blades are inserted in the slots, and means for mounting the insert and key in diierent angular positions about the longitudinal axes of the connector and plug respectively. l

5. A multi-wire connector and plug comprising an insulating body member, spaced stationary contacts mounted therein, a plug, spaced contacts mounted in the plug adapted to engage those of the body member by a relative longitudinal movement of the plug and body member, interlocking means to prevent separation of the plug and body member mounted to become effective by a relative turning movement between the plug and body member While the contacts of the plug and body member are continuously in engagement, an insert in the body mernber provided With a'key opening havingseccentric portions, means mounting the insert in the body member for limited turning movements therein including means Ifor mounting it in different angmlar positions in the body, and a key projecting from the plug of the same shape as the opening in the insert and positioned in the same position relative to the axis of the plug body and the contacts thereon as is the opening in the insert in relation to the axis of the connector body `and the stationary contacts so as to enter said opening only when the plug contacts are in position to engage predetermined contacts of the body member, said insert adapted to turn with the key during -relative turning movements of the body member and plug to and from the interlocked position.

6. A multi-wire connector according to claim 5 in which the key opening includes a rectangularly shaped slot at least a portion of Which is eccentrically located in the end of the insert, and the key in the plug includes a similarly shaped and located rectangular portion for insertion therein.

References Cited in the le of this patent UNITED STATES PATENTS 1,700,437 Hubbell Jan. 29, 1929 2,102,625 Hubbell Dec. 21, 1937 2,731,615 Hazen a Ian. 17, 1956 FOREIGN PATENTS 374,179 Italy 1 Aug. 17, 1939 k630,333 Great Britain Oct. 11, 1949 

